Electric discharge machines (EDM) can use a fine brass electrode wire for arcing electric current across a gap with a steel or other conductive metal workpiece, for cutting through the workpiece. The electrode wire is trained over rollers located on opposite sides of the workpiece so as to be stretched tight while being oriented transverse to the workpiece, and the wire and workpiece are moved relative to one another to trace out a cutting path through the workpiece while the rollers are powered to axially shift the wire during this cutting operation. The electrode wire is continuous, being unwound from a spool and feed through the EDM and past the workpiece, and then being discharged from the EDM while yet unitary with the spool wire. The discharged electrode wire is then collected in an underlying removable container, to be salvaged as scrap.
Most specifics of the EDM unit 1 are immaterial for the purpose of this invention, so that it is only schematically illustrated in FIGS. 1, 2 and 5, except for a few details. Thus, the used electrode wire 2 is illustrated as being discharged along a horizontal path until powered drive roller 3 and idler rollers 4, 5 (see FIGS. 1-e and 5) redirect it to a generally downward path, illustrated vertically (but certain other EDM units might instead discharge the used electrode wire downwardly and inclined at only a slight angle, possibly 15 degrees, from the horizontal). Most commonly nonetheless, the discharging electrode wire 2 is then pushed axially from between the rollers 3, 4 and allowed to fall under the influence of gravity vertically into the confines of an underlying large open top container 6, such as a 40 gallon fiber drum or garbage can. Typically there is no specific guide structures to influence how the wire piles up in the container.
As the axially advancing used electrode wire is fine (typically between 0.006" and 0.012" OD), it has little strength against axial compression and guide tubes or the like must be used if it is to be axially advanced along a specific path or it otherwise will bow or even kink laterally of itself. Once discharged for the EDM, without guide tubes, the axially advanced electrode wire 2 will randomly weave laterally around or back and forth to pile up on itself in the container 6, being laterally redirected and/or even kinked by the container side wall or the wire pile 7 itself. As a result, the wire pile 7 contained within the container is mostly made up of air gaps between crossed layers of the wire, and the wire pile tends to grow vertically quite rapidly so that frequent operator attention is needed to manually pack the wire pile down heightwise and/or to replace the filled container. Without these precautions, the discharged electrode wire can become entangled with nearby machine components including the rollers 3, 4, 5 that could lead to an EDM malfunction. Also, the very low wire weight/container volume ratio dictates the need for using large collection containers, and the need for similar floor space proximate the EDM and on any vehicle shipping the containers to the scrap dealer, to make the whole-wire mode of scrap collection most inefficient and ineffective.